<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>相对路径</title>
</head>
<body>
    <!-- 1.jgp -->
    <img src="./1.jpg" >

    <!-- 2.gif -->
    <img src="./images/2.gif" >

    <!-- 3.jgp -->
    <img src="../3.jpg" >

</body>
</html>